Collision of a vortex with a vaporizing droplet

Three-dimensional interactions between an advecting vortex tube and a vapor izing droplet, described by the Navier-Stokes, energy, and species equation s, cause fluctuations in the droplet heating and vaporization, manifested b y temporal and time-averaged variations in the droplet Nusselt and Sherwood numbers. Stefan flux not only inhibits the droplet heating, it also 'block s' the influence of vortex collision on the droplet interface inhibiting Nu sselt number perturbations. The Stefan flux has a primary effect on the Nus selt number and a secondary one on the Sherwood number. Fluctuations in She rwood number can be significant in magnitude and exhibit self-similarity in both the temporal and time-averaged response. Derived correlations are dem onstrated to be valid for at least three common fuel droplets (n-heptane, n -octane, n-decane). Furthermore, they quantify the effect of vortex collisi on on the droplet vaporization and compliment the accepted correlations for droplets in axisymmetric hows. It follows that, in spray combustion system s, vortical structures could significantly affect transport mechanisms, vap orization rates, and local mixture ratios. (C) 2000 Elsevier Science Ltd. A ll rights reserved.